[PATCH] LoongArch: KVM: Fix memory leak in kvm_loongarch_env_init() error path

[Chaithanya Lagisetty]

kvm_loongarch_env_init() allocates the per-CPU kvm_context (vmcs) and
kvm_loongarch_ops, and registers the perf callbacks, before registering
the IPI/EIOINTC/PCH-PIC/DMSINTC KVM devices. If any of those device
registrations fails, the function returned the error directly without
freeing vmcs and kvm_loongarch_ops or unregistering the perf callbacks.
kvm_loongarch_init() propagates the error without calling
kvm_loongarch_env_exit(), so these resources are leaked.

Unwind the already-acquired resources on the error path, mirroring
kvm_loongarch_env_exit().

Fixes: c532de5a67a7 ("LoongArch: KVM: Add IPI device support")
Signed-off-by: Chaithanya Lagisetty <nagachaithanya9911@xxxxxxxxx>
---
 arch/loongarch/kvm/main.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/arch/loongarch/kvm/main.c b/arch/loongarch/kvm/main.c
index 3e1005526f4b..685d334cf957 100644
--- a/arch/loongarch/kvm/main.c
+++ b/arch/loongarch/kvm/main.c
@@ -385,22 +385,33 @@ static int kvm_loongarch_env_init(void)
 	/* Register LoongArch IPI interrupt controller interface. */
 	ret = kvm_loongarch_register_ipi_device();
 	if (ret)
-		return ret;
+		goto err;
 
 	/* Register LoongArch EIOINTC interrupt controller interface. */
 	ret = kvm_loongarch_register_eiointc_device();
 	if (ret)
-		return ret;
+		goto err;
 
 	/* Register LoongArch PCH-PIC interrupt controller interface. */
 	ret = kvm_loongarch_register_pch_pic_device();
 	if (ret)
-		return ret;
+		goto err;
 
 	/* Register LoongArch DMSINTC interrupt contrroller interface */
-	if (cpu_has_msgint)
+	if (cpu_has_msgint) {
 		ret = kvm_loongarch_register_dmsintc_device();
+		if (ret)
+			goto err;
+	}
 
+	return 0;
+
+err:
+	kvm_unregister_perf_callbacks();
+	kfree(kvm_loongarch_ops);
+	kvm_loongarch_ops = NULL;
+	free_percpu(vmcs);
+	vmcs = NULL;
 	return ret;
 }
 
-- 
2.43.0